Case Study: Tempe Arizona mixes WiMax and Wi-Fi mesh

The options for municipal wireless are expanding - a US city adopts a mix of technologies.

By
Joanie Wexler, Network World
| Oct 13, 2005

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Starting this summer, certain businesses and residences in Tempe, Arizona, got both fixed and mobile broadband services available to them from a common Wi-Fi mesh network infrastructure.

The city is having the network installed in part to support all mobile municipal personnel (police, fire and water department workers and building inspectors) with broadband at vehicular speeds, says Dave Heck, deputy CIO for the city.

But Tempe has also licensed the network to a wholesale service provider so commercial services can be provided citywide. Businesses, for example, will have a wireless T-1 alternative with mobility tagged on as an extra throughout the 40-square-mile Tempe area for about 20 percent less than the cost of a terrestrial T-1 in the area today, says Bruce Sanguinetti, president and CEO of NeoReach Wireless, the company that won the Tempe wholesale bid.

In September, NeoReach will begin bringing up Tempe’s six zones over a six-month period. The entire city should be covered by February.

400 access pointsThe Wi-Fi mesh infrastructure, manufactured by Strix Systems, will comprise 400 access points used for both backhaul and access, says Sanguinetti. Strix’s routing algorithm supports handoffs among APs at vehicular speeds up to 180 miles per hour, he says.

Heck adds that many emergency responders’ laptops will be outfitted with PadCom client software to facilitate roaming among the Wi-Fi network and older, lower-speed public safety networks.

There will be six points of OC-3 ingress connected to 802.11a access points with single or double radios for backhaul within dense populations. There is a 4.9 MHz slot in the Strix mesh devices to support WiMax at the outer edges; WiMax will eventually be used to connect pockets of dense populations across the county.

Mesh and WiMax combine“We specified mesh for within city limits, because it is the only metro-scale technology available today,” says Heck. “WiMax provides longer range, but doesn’t offer good end-user availability. If you install a base station on a street light, it’s good for reaching 10 miles out, but not for supporting a user who’s right near it.”

The Tempe deployment is the latest in a series of municipal rollouts aimed, at least in part, to provide broadband competition when incumbents haven’t stepped up to the plate with creative new services. Some deployments have resulted in litigation by incumbents. Heck says he doesn’t expect any flak, because the city isn’t assuming the role of commercial network operator, and the project was put out for competitive bid.

Sanguinetti adds that incumbent cable operator Cox will likely team with NeoReach to add mobility services to its cable-based broadband services.